Performance evaluation of cryogenic treated and untreated brass electrode in wire-EDM

Abstract

ABSTRACT WEDM is regarded as a specialized thermo electric cutting process for precise machining in a wide range of materials with varied hardness and complex geometries that curtails utilization of conventional machining methods. The technology of WEDM process requires electricity to penetrate through a material with a thin conductive wire electrode as the tool. In this study, an untreated and deep cryogenic treated (196°C) brass wires are used to experiment with different machining variables such as peak current (IP), tension in the wire, pulse on time (TON), servo feed rate (SF), and pulse off time (TOFF). Monel 400 alloy, a work material that has high mechanical strength and corrosion-resistant properties, for which the output responses such as Surface Roughness (SR) and Material Removal Rate (MRR) are investigated. Taguchi L27 orthogonal array was selected to formulate the design of experiments and to inquire the response of each variable from the output responses. The most influencing parameters such as pulse-on time on MRR, pulse-off time as contributing parameter in surface roughness and wire tension playing a vital role in kerf width were determined by the analysis of variance. MRR is greater with untreated brass wire than cryogenic treated brass wire. Cryogenically treated brass wire provides leverage over untreated brass wire in Surface Roughness and Kerf width. Surface morphological study proves that workpiece machined by deep cryogenic treated wire electrode provides better surface finish over untreated wire electrode which has large pores, voids, and unevenly distributed re-solidified particles. Experimental results are provided to verify this approach, and conclusion is to be drawn on the wire electrode with most phenomenal aspects.